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The Scientist Who Explored the Skies

APF Fellow

MT. PALOMAR - Visiting the Palomar observatory in the forested mountains northeast of San Diego is a bit like finding oneself at the foot of one of the great pyramids of Egypt. The scale is so intimidating, so outsized compared to its surroundings, that you are struck by the feeling that those who created this thing were grander and more daring than we are today.

For nearly fifty years in the second half of the 20th century, the famous “Big Eye” dominated worldwide astronomical research and discovery. Virtually everything we know about the universe today was either proved or hinted at by the images captured in the giant 200-inch mirror, which was such an engineering marvel that curiosity-seekers crowded the tracks to see it pass by on its journey from the Corning Glass Works in New York to Southern California.

The ambition of its builder, George Ellery Hale, who famously said, “Make no small plans, Dream no small dreams,” is in every detail. The Art Deco dome is “as tall as the Roman Pantheon,” said Dan McKenna, squinting at the gleaming structure, white as polished marble in the afternoon sun. “When the builders realized it was going to be nearly that tall, they decided to make it tall enough to match the Roman structure.”

McKenna is the middle-aged superintendent of the facility; he’s a taciturn man, not much given to sharing personal information. Asked his age, he replied, “Roughly, 13.8 billion years.” That is, of course, the age of the universe, give or take a few hundred million. Scientifically speaking, he’s right. The atoms contained in our bodies were in fact brought into existence in those micro-seconds after the Big Bang.

There are bigger telescopes around today and more are on the way. But McKenna, who wears three communication devices on his belt in case of fire or other disaster, insists Palomar is no creaky antique. “The 200-inch is still used every night,” he said. They’re even planning a new instrument up there. Called the Zwicky Transient Factory, it will be the most powerful and nimblest telescope ever built to search for supernovas, the giant exploding stars that light up the heavens in their suicidal agonies.

Named for the Caltech astrophysicist Fritz Zwicky, the project is a long overdue acknowledgement of the debt owed to one of the most intriguing and confounding scientists of the last century, a man capable of astonishing leaps of imagination and almost equally amazing eruptions of bilious indignation toward those who failed to appreciate his genius.

In a remarkable burst of creativity in the early 1930s, the Swiss-born scientist announced a new type of exploding star that he named a Super-Nova. That discovery would help his colleague, Walter Baade -- who later fell out with Zwicky amid accusations that one or the other had released a rattlesnake in the observatory to kill his rival – determine the age of the universe. Zwicky also predicted the existence of a compact star made up entirely of densely packed neutrons, a crucial first step on the path to the discovery of Black Holes. Totting up the mass of the stars in the famous COMA galaxy cluster, he made an even more startling prediction: There must be some invisible material in the universe that keeps the biggest structures from flying apart. Now known to make up much more of the “stuff” in the universe than all the stars and asteroids and comets and planets put together, Dark Matter is the hottest topic in astrophysics. Scientists around the world are searching for the Dark Matter particle, which is so elusive it can pass through the Earth without disturbing a butterfly’s wings. Yet is so powerful that without it we would not recognize the night sky.

“In my mind there were two great astronomers of the 20th century,” said Caltech astrophysicist Shri Kulkarni, the principal scientist for the forthcoming Zwicky telescope, which is due to come on line in two years. “One was (Jan) Oort (who overturned the idea that the sun was at the center of the Milky Way) and the other was Zwicky.”

“He was kind of a hero to me,” recalled Gerald Wasserburg, who taught geology and physics at Caltech when Zwicky was there. “Fritz did truly imaginative things. He figured, if there were neutrons, why couldn’t you build a star out of them?” The neutron had only been discovered the year before Zwicky’s (and Baade’s) prediction.

Today, in the Palomar visitor center, there is a picture of Zwicky sitting at his favorite instrument, the unprepossessing 18-inch Schmidt telescope, the first to be located on Mt. Palomar. The Schmidt’s chief virtue was its wide field of view, which allowed the observer to scan large areas of the heavens. Astronomy at the time relied on glass photography plates, which astronomers searched like jewelers looking for changes in the heavens over weeks and months. The work was tedious and mind-numbing. Zwicky figured out how to improve the process by making positive and negative plates of the same part of the sky. Stars that hadn’t changed would cancel each other out, highlighting any differences. It was perfect for finding supernovas, which can burst out anywhere at any time. Although the remnants of some supernovae can be seen hundreds or even thousands of years later, the key to understanding their behavior (some of the heaviest elements in nature can only be made in a supernova) is catching them in the act of blowing themselves apart.

Beginning in 1936, finding supernovae became an obsession with Zwicky. By the time of his retirement he had found 123, which was more than the rest of the world combined.

But Zwicky was far more than a theoretician and observer of the heavens. Quotable and fearless, bold and controversial, he was one of the first celebrity scientists, that elite class of mid-20th century sages who were going to usher in a utopian future in the age of transistor radios and missile-gap hand-wringing.

One time Zwicky, who grew up climbing mountains in Switzerland, mounted a rescue mission on Mt. Whitney. Another, he announced that he’d invented a new way to affix a stamp on an envelope. You lick the envelope, not the stamp, which tastes terrible. Reporters who chronicled his exploits dutifully publicized his philatelic discovery as eagerly as they described his prediction that we would soon be living on the moon.

After World War II he went to Germany to de-brief Hitler’s V-2 rockateers, returning with secrets that helped launch America’s space program. In gratitude, President Truman made him the first foreigner to receive the Presidential Medal of Freedom. After the humiliation of Sputnik, it was Zwicky who launched the first objects into outer space. As a public intellectual he drew media attention everywhere he went. Maybe not as much as Einstein, but Zwicky was a far better quote, perfectly happy to call his enemies “spherical bastards.” That meant that whichever way you looked at them they were bastards. This was Zwicky at his best, utilizing the language of science in the service of score-settling.

In 1964, a writer compared Zwicky to one of his beloved supernovae. “For supernovae are highly explosive and controversial objects. And few scientists are more explosive and controversial than professor Zwicky. Wherever the professor’s iron-grey head appears…ears begin to strain for sounds of new pronouncements.”

Zwicky was particularly outspoken about the injustices he felt he had to bear from the science community, which can be as clubby and vindictive as a frat house. Wasserburg recalled sitting next to Fritz during physics colloquia, at which eminent scientists would present their latest findings. It was designed to be a collegial, relaxed setting, but Fritz would have none of that. “He was an extravaganza,” Wasserburg recalled. “He had this booming voice. ‘Shit, I say that’s shit,’ he would shout” whenever he disagreed, which was often.

More frequently, he would simply throw up his arms and say, “What’s new? I discovered that 30 years ago.”

Seth Shostak, the senior astronomer and director at SETI, the group searching for intelligent life elsewhere in the universe, was a student at the time. “As students we were amused” by the frequent outbursts, he said. Only in time did Shostak realize there was a lot of truth in Fritz’s eruptions. And in his complaints about not getting telescope time at Palomar. Observatories can be very political places and time on the telescope is the lifeblood of an astronomer’s work. Simply put, an astronomer kept from the telescope is not an astronomer.

Not all of Zwicky’s ideas were good. Typical of many very creative people, he had few filters. What occurred tended to emerge, pure and unedited. During the Cold War, the Swiss government recruited their ex-pat favorite son to advise them on defense preparations against a potential Soviet attack. He urged them to station a fleet of jet fighters underwater in Swiss lakes, from where they could emerge like flying fish. Another suggestion was to build something called a Terrajet, a comic book weapon that could chew through the Earth and erupt without warning in Red Square or Tiananmen. Needless to say, the Swiss politely thanked Fritz and ignored his ideas.

“Fritz reminds me of (Johannes) Kepler,” said George Djorgovski, a Caltech researcher who is one of Zwicky’s most ardent fans. “He was a mystic and astrologer. But in this big mass of nonsense are the three Kepler laws (which explain planetary orbits in the solar system).”

Fritz never stopped dreaming. He went right on looking up into the heavens and spewing vitriol when necessary. After his death in 1974, he was all but ignored by the newspaper writers who once so breathlessly recounted his exploits and magmatic ejecta. But in his field some stepped forward to pay tribute. Cecilia Payne-Gaposchkin of Harvard, a great astrophysicist in her own right, wrote that the “man who gave us so much of what is known about supernovae, galaxies and clusters of galaxies has placed the world in his debt. Astronomy will never be the same again.”

That was true enough, but most of the rest of the world quickly forgot his name. Now, with the hunt for Dark Matter on in earnest and money being raised for the new Palomar instrument, the world may finally be ready to repay that debt. A collaboration of Caltech, the University of Wisconsin and a host of other institutions the Zwicky Transient Factory will be able to discover a new supernova within 24 hours of its eruption, helping scientists to learn even more about how the universe is built, torn down and redeveloped like a blighted neighborhood.

“We have Chandra, Spitzer, Hubble, (telescopes named for famous scientists) but nothing for Fritz,” said Kulkarni. “I hope this will be the first of many recognitions.”

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John Johnson Jr. is examining the achievements of Fritz Zwicky and the story of dark matter during his Alicia Patterson fellowship.